There may be no single cause of bipolar disorder (aka manic depression). Instead, research indicates the causes of bipolar disorder are probably a combination of biochemical, genetic and environmental factors that may trigger and perpetuate the chemical imbalances in the brain.
Net worth: $829 million. Telecommunications mogul Strive Masiyiwa is widely regarded as the richest man in Zimbabwe and is one of the richest men in Africa with a net worth of more than US$800 million.
Robert Gabriel Mugabe, President of Zimbabwe. First prime minister (1980â ) and president (1987â ) of Zimbabwe, born in Kutama, Zimbabwe (formerly Southern Rhodesia). Largely self-educated, he became a teacher in 1942.